Heat exchange is an important design consideration. Heat exchangers such as heat sinks or heat emitters can benefit many systems by transferring heat away from, or to, a heat source. There are a number of attributes to consider when designing a heat-exchange system to cool another system. Size, mass, cost, performance and reliability each are important factors. In order to address some or all of these factors, systems can be designed in which a cooling fluid is circulated nearby a heat source to cool the heat source. Such systems can include pumps to circulate fluid. Small, low-cost designs are desirable.
Existing micro-fluidic pumps are small, but they can be unreliable, expensive, and can have many moving components, including sensitive microvalves prone to breaking. They can be quite inefficient with large transducer power consumption and large leakage flows. Many require strong electrostatic forces or other forces that cannot be efficiently generated at small scales. Mechanical micropumps can be used but they can be affected with some of aforementioned problems.